Engine Gurus – Cam Timming Question

[XS11UFO]

I did the valve clearance by removing the cams, got it back together and she was finally starting to run really good (still working on final sync on the carbs after rebuild / clean). The mileage is a little over 25k and even though I read about on this forum many times I didn’t do the ACCT mod while I was doing the valves (wish I had). I figured with only 25k the manual CCT would hold up for a little while. I took it out for the 5th test ride (only 3 miles) and she was purring when I started hearing a lot of noise from the top end and she started running rough. I babied it home and resolved to do the mod immediately – I thought the CCT got loose and the chain was slapping. I did the ACCT mod and started it and the top end is still making a lot more noise than usual (and she is idling rough). I know with the valve clearances loosened up there will be more noise – but this is a lot. OH S&^%! I kissed a piston, bent a valve, busted a cam cap and generally blew any chances of riding for at least a month while I redo the top end.

So now damage analysis – I checked the compression (while warm, with plugs out, WOT) and got 160, 165, 165, 165. Sweet! So the next thing I check is the cam timing. I took the faring and valve cover off today and the cams look close, but not balls on. When I did the valves I think I remember the cam marks were only slightly off and I redid it and they came out balls on. To me the exhaust cam looks slightly retarded and the intake cam very, very slightly advanced. My question is 2 parts. One tooth on the cam sprocket looks like it would make too large an adjustment on the exhaust much less the intake. If this timing looks ok to you guys what do I look for now? Thanks in advance for the expertise I know you are about to share! Now the Pictures (I know you love them).

1st the Crank Position Indicator.


Next the Intake Cam Timing Mark


Last the Exhaust Cam Timing Mark


She was almost together




I REALLY wish I had done the ACCT when I did the valves!

[DAVINCI]

your timing is fine, leave it. In fact, it's closer to perfect than mine is! you can do the ACCT anytime, no need to take off the valve cover. JUST DON'T TURN THE CRANK WITH THE TENSIONER REMOVED.

While you have the top open go ahead and re-check your clearances.

[BA80]

Those cam positioning marks are not always perfectly lined up. What you have there looks real good.

Since you removed the cams to do the shims I would suggest you check to make sure your cam caps haven't worked loose. I have seen that happen.

That'll make those valves noisy.

[bikerphil]

You might have an exhaust leak where the headers bolt to the head. This can cause a louder than normal ticking noise. Make sure your spark plug caps/wires aren't arcing too, JAT. Cam timing marks look fine to me.

[WMarshy]

How rough was it running...like lost a cylinder rough or what? You might want to check the wires going to your advance under the left hand cover...

BTW, I second the timing marks, looks great! Double check the clearance and cap torque while the cover is off...

[DGXSER]

Well, I would tell you your timing marks look great, but I might need my other hand to count to the whatever'th number I would be.... But yeah, they look finer than frog hair to me.

Anytime you pull the CCT (Auto or not) make sure the bike is level, like on the centerstand, not the side stand. From there, make sure the C mark on the timing plate is lined up with the indicator, and go for it.

As for your rough running, yeah, check the valve clearances again. would be my first thought.

[skids]

What the heck is ACCT? If you were to try and adjust the chain one tooth on the exhaust or the intake, you would be way off on the marks. Finish up with the vacuum synch and the pilot screw adjustment. Neither has much influence on high throtte/rpms but a lot do do with low to midange.

[BA80]

Skids, where ave you been?

Automatic Cam Chain Tensioner.

[XS11UFO]

Thanks

Ok, timming is ok; I will check clearances; check cam caps; I didn't pull the ACCT, just the valve cover; it was pretty rough it would idle just not well and it seemed to run a lot better before the noise started; check the exhaust bolts and plug / wire arcing.

Thanks for the extra eyes / thoughts, I will update after doing the work. Tempeture and Olympics allowing - tomorrow.

[mack]

Cam chain

I believe that Scot or Motoman had a discussion about a year ago about the intake being dead on and the exhaust being off a slight bit like yours as an indicator that the cam chain is starting to wear. The more the exhaust is off the greater the stretch. Yours look good but check every 6k miles.

[XS11UFO]

I did the ACCT mod and checked the tension when I did it. The Raptor ACCT was in the 1st notch so there should be lots of chain left and with 25k miles that is what I would expect.

Today's update - sure enough, the cam cap nuts were all too loose. I will check valve Clarence tomorrow.

[BA80]

I had valve noise that was getting louder and louder on my SG when I first got it and it turned out to be the cap nuts. 2 or 3 had actually fallen off before I found the problem.

Someone had used the cam loosening method to adjust the valves befor I got it and didn't get the caps properly torqued.

That is one reason I recommend using the cam adjusting tool. When you take the cams loose it not only leaves you open to this but the more the cam bolts are loosend and retightened the more likely your going to pull the threads on the head.

It just takes some mechanical ability to figure the tool out.

You do have a torque wrench don't you?

[XS11UFO]

Yes, and I used the torque wrench the 1st time but with the torque so low (7.2 Ft. Lbs.) I should have considered heat cycles. In other applications it is recomended to run it through a heat cycle to check final torque - I should have done that.

i would be happy to try the tool - just havn't picked one up yet.

[XS11UFO]

Opinions please

Since the cam caps came loose I have worried about a repeat - what about blue locktite on the cam cap nuts?

[crazy steve]

Can't hurt.....